EA032688B1 - Edge strip, furniture panel and method for producing a strip - Google Patents

Abstract

The invention relates to an edge strip, especially for panels of pieces of furniture, comprising a hot-melt layer which consists of at least one easy-flow polyolefin and the rheological behavior of which can be controlled by means of the melt flow rates of the polyolefins used in hot-melt layer. The invention further relates to a method for producing an edge strip of said type as well as to a panel for pieces of furniture that is connected to an edge strip of said type.

Description

The invention relates to an edge band, in particular for furniture panels, containing a melt layer, which consists of at least one free-flowing polyolefin and whose rheological properties can be controlled using the melt index of the polyolefins used in the melt layer. In addition, the invention relates to a method for producing said edge band, as well as to a furniture panel associated with said edge band.

Thermoplastic finishes are known from the prior art for a snug fit to an uncoated chipboard, in particular front faces, countertops, fixtures, ceilings and side wall systems. Examples of finishing materials are PVC-based plastics, ABS-based plastics, PP-based plastics and PMMA-based plastics. Typical edge thicknesses of these tapes are between 0.4 and 3 mm.

The expressions of an edge band and an edge band are used synonymously for the method of the present invention.

In accordance with the prior art, these thermoplastic finishes can be adhesively bonded to a chipboard using hot-melt adhesive. The adhesive bond between the edge band and the trimmed edge of the chipboard in this case covers the entire surface.

In the prior art, edge strips are described which comprise a melt layer provided for reducing costs associated with the use of hot-melt adhesive during processing of these thermoplastic finishes. This makes it possible to weld the tape for the edge with wood-based material, for example, using laser technology or other methods of introducing energy.

In order to ensure good adhesion between the edge band and the wood-based material, the polarity of the plastic material on which the melt layer is made is of great importance in this case. DE 202007011911 U1 describes an edge band containing a melt layer, in which the melt layer contains both polar and non-polar particles in the structure of the molecule. This feature is intended to achieve a particularly effective adhesive bond between the edge band and the wood based material. In this case, the melt layer, as a rule, is made on the basis of a grafted copolymer, in particular polypropylene with grafted maleic anhydride.

This type of melt layer has the following disadvantages: the need for graft copolymerization to modify the polymer material in the melt layer leads to an increase in costs. When using these materials, moreover, often weakening points arise in the resulting adhesive bond between the edge band and the wood-based material, and in particular on corner joints (finish / finish weld), this leads to insufficient water resistance and water vapor.

Thus, it is an object of the present invention to provide an edge band that, when compared with the prior art, has economic advantages in providing improved adhesive bonding.

The objectives of the invention are achieved by edge banding, as stated in the idea of claim 1, and the dependent claims include at least the preferred embodiments and improvements. Moreover, the objectives are also achieved by means of a furniture panel, as claimed in paragraph 26 or 27 of the claims, and a method, as claimed in paragraph 28 of the claims.

Accordingly, a tape is provided for the edge, in particular for furniture panels, comprising a melt layer, in which the melt layer contains a thermoplastic polymer consisting of non-polar monomer units. It is preferable that the thermoplastic polymer consisting of non-polar monomer units is a polyolefin.

Unexpectedly, it was found that contrary to the prevailing opinion among specialists in the given field of technology, for the formation of a good adhesive bond between the edge band and the wood-based material, a melt layer based on a polymer containing both polar and non-polar particles in the molecule structure is required it is possible to achieve excellent results with an edge band whose melt layer contains a thermoplastic polymer consisting only of non-polar monomer units. It has been found that contrary to the idea in DE 202007011911 U1, this type of edge band can provide an excellent bond between the edge band and the wood based material.

The expression of non-polar monomer units is known to those skilled in the art. For the purposes of the present invention, this expression is intended to describe a thermoplastic polymer consisting of non-polar monomer units, in particular a thermoplastic polymer, which is a combination of homopolymers or a copolymer of polyolefins.

The term polarity when used in chemistry means the formation of separate charged centers, which are obtained by displacing a charge within groups of atoms, and the effect of which leads to the fact that the group of atoms is no longer electrically neutral. An electric dipole moment is a measurement of the polarity of a molecule. A polar substance is made up of polar molecules,

- 1 032688 which are characterized by a constant electric dipole moment. In contrast, a nonpolar or apolar molecule does not have a constant dipole moment.

In a particularly preferred embodiment of the present invention, there is provided an edge band, in particular for furniture panels, comprising a melt layer that contains a thermoplastic polyolefin.

In a most preferred embodiment of the invention, an edge tape is provided comprising a melt layer which consists of at least one thermoplastic polyolefin, or whose polymer base consists of at least one thermoplastic polyolefin, and which optionally contains other components, in particular in the form of pigments , fillers and additives.

It is preferable that the thermoplastic polyolefin is a combination of homopolymers or a copolymer of ethylene, propylene and / or butylene. Most preferred is that the thermoplastic olefin is a combination of propylene homopolymers or a copolymer of polypropylene and polyethylene.

Surprisingly, it has been found that this type of edgeband provides excellent results in (adhesive) bonding with wood based material. In this case, (adhesive) binding can be achieved by introducing any type of energy required. In a particularly preferred embodiment, the (adhesive) bonding of the edgeband to the wood based material is achieved by laser exposure, exposure to hot air, plasma exposure, exposure to ultrasound, or any other other technology required to introduce energy. Most preferred is that the (adhesive) bonding of the edge band to the wood based material is achieved by laser exposure.

In the case of laser welding, the laser radiation is concentrated by suitable optical means, thus melting the melt layer. This makes it possible to weld the tape for the edge with the substrate. In a similar method, it is also possible to use plasma to melt the melt layer.

In the case of ultrasonic welding, the energy required for welding is generated by ultrasonic vibrations. Ultrasonic vibrations induce the movement of the molecules of the polyolefin-based material to the corresponding areas, causing friction, which, in turn, leads to the melting of the plastic.

Another possible way to achieve this type of melting of a polyolefin-based material for welding purposes is through the controlled use of hot air.

Moreover, there are also other known methods that can be used to melt the polyolefin of the melt layer by introducing energy to enable sequential welding with the substrate.

It was found that the processing properties, in particular the flowability, of the melt layer of the edge band according to the invention can be very effectively controlled by the melt flow index of the polymer, on the basis of which the melt layer is made. In a preferred embodiment, the melt flow index (MFI) of the polymer on the basis of which the melt layer is made is more than 25 g / 10 min, preferably 100 g / 10 min or higher, especially preferably higher than 100 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg). In particular, good results are obtained when the melt flow index (MFI) of the thermoplastic polymer on which the melt layer is based is> = 1000 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg), in particular from 1000 to 1500 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg) and, in particular, preferably 1200 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg).

Thermoplastic polymers having the aforementioned values of the melt flow index or the values of the melt flow index in the aforementioned ranges have an advantageous property of free flowing.

It was particularly found that the use of thermoplastic polymers with a melt flow index <100 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg) in the melt layer has an adverse effect on the processing properties of the edge band according to the invention, since then the melt layer is no longer sufficiently free flowing. In particular, it is true if the polymer base of the melt layer consists of thermoplastic polymers that consist of non-polar monomers.

Therefore, in a preferred embodiment of the invention, an edge tape is provided comprising a melt layer whose polymer base consists of at least one free-flowing thermoplastic polymer, preferably at least one free-flowing polyolefin, in which the melt layer optionally also contains other components, in particular in the form of pigments, fillers and additives.

In the most preferred embodiment, therefore, the melt layer consists of a polymer base, which is completely non-polar.

It was found that when choosing these MFI values for the thermoplastic polymer layer

- 2 032688 of the melt, it is possible to achieve an improvement of (adhesive) bonding with the wood based material, since the penetration of the wood based material by the polymer of the melt layer is improved.

To achieve an ideal result, the MFI value selected for the thermoplastic polymer of the melt layer may depend on the nature of the wood based material. As the MFI values increase, the depths of polymer flows into the wood based material and the edge adhesion values increase and therefore improve. The advantage of a greater depth of flow is that the cracks that are usually present in practice in the surface material of a furniture panel are filled more satisfactorily with the inflowing material based on the melt layer. The resistance of the water bonded at the edges of the panels of the invention according to the invention is thus increased, and the risk of swelling of wood-based panels is thus reduced.

In a particularly preferred embodiment, the edgeband melt layer according to the invention comprises a mixture or combination of thermoplastic polymers that consist of non-polar monomer units and have different melt flow indices. In a particularly preferred embodiment, in this case, the melt flow index of one of the polymer components of the melt layer is from about 50 to about 200 g / 10 min, preferably 100 g / 10 min or higher, in particular, preferably from 100 to 200 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg) and the melt flow index of the other component is from about 1000 to 1500 g / 10 min, preferably 1200 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg).

It is particularly preferred that the melt flow index (MFI) of a mixture or combination of thermoplastic polymers that are composed of non-polar monomer units is 200 g / 10 min or higher, preferably in the range of 400 g / 10 min to 1000 g / 10 min ( in accordance with ISO 1133, 230 ° C, 2.16 kg).

The required MFI of the melt layer can be established by selecting the appropriate ratio of the components of the mixture of different polymers with excellent MFI. An example of a preferred mixture ratio is the ratio of homopolypropylene (MFI 1200): homopolypropylene (MFI 120) 25: 75.

By using this type of polymer blend with different melt flow indices, it is possible to achieve perfect matching of the edgeband with various wood-based materials. Perfect match means controlling the flowability of the melt layer of the edgeband according to the invention and the associated improvement in the adhesion of the edgeband on the edge of the furniture panel.

An important factor in this case is the pore size of the corresponding wood based material. The larger the pore size of the corresponding wood-based material, the higher the possibility of improving the (adhesive) bonding of the edge band according to the invention by increasing the quantitative ratio of the polymer with a higher melt flow index: for example, the cavities to be filled with the melt of the melt layer are much larger in chipboard than in MDF (medium density fiberboard). Ideal (adhesive) bonding with wood-based materials with a relatively high pore density can be achieved by choosing a polymer with a higher melting point index or by shifting the ratio of the components of a mixture of two polymers relative to a polymer with a higher melting point index. This increases the fluidity of the melt layer and at the same time improves the penetration depth of the polymer into the wood based material. Thus, a control method is available that can be applied to separately optimize the edge band according to the invention with respect to specific wood-based materials.

Thus, the edge tapes according to the invention achieve better adhesive bonding characteristics than the edge tapes described in the prior art regarding wood based materials, without any need for expensive grafted copolymers.

The advantage of using mixtures or combinations of polymers with different MFI values in the melt layer is that with polymers having different MFI values, it is possible to influence not only the penetration depth, but also the adhesion of the finish to the panel. Increasing the MFI values of these mixtures or combinations not only increases and thus improves flow depths and adhesion properties, but also improves controllability of flow depths and adhesion properties. The advantages of the edge band according to the invention are even more apparent with blends or a combination of polymers with different MFI values in the melt layer: i.e. cracks typically present in practice in panel surface material can be more satisfactorily filled with inflowing material based on the melt layer. At the same time, the residual thickness of the melt layer sometimes decreases sufficiently with increasing MFI of the material of which the melt layer consists, since the flow of the melt layer improves (see Figs. 1-3). This leads to a larger edge of the melt between the panel and the tape for the edge, and the specified edge, in turn, has a predominant effect on the tight fit of the panel to the finish. The resistance of the water and water vapor bonded at the edges of the panels can thus increase, and the risk of swelling of wood-based panels can thus be reduced.

However, the above two effects may also have adverse effects. Surplus

- 3 032688 the flow of the melt layer can, under the influence of the force of attraction, lead to the edge of the melt of various sizes on the upper side and the lower side of the wood-based panel equipped with an edge band. On the lower side, the material of the melt layer flows downward from the panel, and the formation of a melt flange on the lower side of the panel is unacceptable. As a result, the tight fit and thus the resistance to swelling caused by water, and in particular caused by water vapor, is less effective on the lower side than on the upper side. Therefore, it was found that it is preferable that the residual thickness of the melt layer present on the panel equipped with the edge tape is> 0.02 mm, preferably> 0.05 mm, particularly preferably> 0.08 mm, most preferably> 0.1 mm It also provides better compensation for structural or surface differences at the edge of a wood-based panel. The stresses between the panel and the plastic finish (caused, for example, by different application and storage temperatures) are absorbed, thereby improving their suitability for long-term use. The residual thickness of the melt layer can be adjusted by selecting or combining thermoplastic polymers with a polymer base of the melt layer with suitable MFI values.

The term bonding is applicable for the purposes of the invention means that when applying an edge band according to the invention to a furniture panel, the polymers of the molten melt layer penetrate into the cavities and pores present in wood-based materials, and when cooled, they solidify so that these cavities and pores are filled free flowing polymer, preferably completely filled. This leads not only to the strong bond of the traditional type of adhesive bonding, but also to the interlocking bond between the tape for the edge, in particular its melt layer, and the material based on the furniture panel wood. At the same time, it is also possible that the non-polar polymer base that makes up the melt layer forms a welded bond with the lignin present in the wood-based panel, since lignin also has thermoplastic properties.

Since the edge band according to the invention does not contain polar groups and preferably also reactive groups in the polymer base of the melt layer, the binding of the edge band according to the invention, in particular its melt layer, is preferably mainly interlocking bonding, particularly preferably exclusively interlocking bonding.

The benefits are the result of additional, or predominant, or exclusive, interlocking bonding between the edge band and the wood panel material of the furniture panel. In particular, the adhesion of the edge band according to the invention to the furniture panel is increased to such an extent that it is no longer possible to achieve non-destructive peeling of the edge band from the furniture component. At the same time, the tight fit of the edge area of the furniture panel is improved, thereby increasing the resistance to water and water vapor associated at the edges of the panels according to the invention and, thus, reducing the risk of swelling of wood-based panels.

Another advantage of the edge banding according to the invention is that the reuse properties are greatly improved. Edge bands for furniture panels usually have a top or decorative layer consisting of a combination of homopolymers, such as polypropylene. If an edge tape is obtained with this type of top or decorative layer made of polypropylene and a melt layer based on a grafted copolymer, a mixture of materials is obtained that provides for the complexity or actual inability to reuse such edge tapes. On the contrary, it is possible to design the edgeband according to the invention in such a way that the top or decorative layer and the functional melt layer are made on the basis of the same polymer, thus allowing easy reuse of the composite tape.

In another preferred embodiment of the invention, an edge band is provided comprising a melt layer whose polymer base consists of a mixture or combination of at least two polypropylene polymers, or a combination of at least one homopropylene and at least one propylene copolymer, wherein the melt layer optionally contains other components, in particular in the form of pigments, fillers and additives.

It is preferable that the various homopolypropylene and propylene copolymers present in the combination have different melt flow indices (MFI), and the melt flow indices of homopolypropylene are in the range of 100 g / 10 min to 1500 g / 10 min, preferably in the range of 100 g / min up to 1200 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg), and the melt flow indices of propylene copolymers are 3 g / 10 min or more, preferably 50 g / 10 min or more , particularly preferably 100 g / 10 min or more (in accordance with ISO 1133, 230 ° C, 2.16 kg).

It is particularly preferred that the melt flow index (MFI) of the mixture or combination of homopolypropylene and propylene copolymers is 100 g / 10 min or higher, preferably 200 g / 10 min or higher, particularly preferably in the range of 400 g / 10 min to 1000 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg).

In a most preferred embodiment, the copolymers used in this mixture

- 4,032,688 or combinations, are copolymers of ethylene and propylene.

The combination of homopolypropylene with copolymers based on polypropylene and polyethylene in the melt layer of the edgeband according to the invention has several advantages.

When using a combination of homopolypropylenes with copolymers based on polypropylene and polyethylene, it is possible to reduce the elastic modulus of the melt layer. The modulus of elasticity is a property used in material technology that describes the relationship between stress and tension during the deformation of a rigid body with linearly elastic behavior. The modulus of elasticity increases with increasing resistance of the material to elastic deformation. A melt layer made of a material with a high modulus of elasticity is therefore more rigid and sometimes more brittle than a melt layer consisting of a material with a low modulus of elasticity. Therefore, a decrease in the elastic modulus by combining homopolypropylene with copolymers based on polypropylene and polyethylene in the melt layer leads to a higher flexibility of the edge band, in particular the melt layer itself.

In the melt layer of the edge band according to the invention, for example, homopropylenes with an elastic modulus of 1500 MPa can be used. The elastic modulus of the used copolymers of polypropylene and polyethylene is, for example, 700 MPa. By selecting the appropriate ratio of the components of the mixture of homopolypropylene and a copolymer of polypropylene and ethylene, it is preferably possible to reduce the modulus of elasticity of the melt layer to 1400 MPa or less, 1200 MPa or less, 1000 MPa or less, preferably 950 MPa or less, or particularly preferably to 800 MPa or less.

In particular, this is important when temperature fluctuations occur. The thermal expansion coefficients of wood-based panels and edge bands are different. Consequently, temperature fluctuations result in a different expansion of the material of the panel based on wood and the top layer of tape for the edges associated with the layer of the melt. This can lead to stresses in the edge tape and to the increased effect of the melt layer of the edge tape on tensile forces. In traditional edge tapes, frequently occurring temperature fluctuations can gradually lead to at least some rupture of the bond between the edge tape and the wood-based panel, and thus gradually to peel the edge tape from the wood-based panel. Thus, water and water vapor can penetrate the wood-based panel. These disadvantages can be overcome by using an edge band according to the invention, whose melt layer has a reduced elastic modulus. Based on the greater elasticity of the melt layer, the stresses and tensile forces that increase during temperature fluctuations on the edge band can be absorbed more efficiently by the edge band, in particular its melt layer, and the break in the bond between the edge band and the wood panel can be reduced to minimize or prevent.

The great flexibility of this type of finish according to the invention also has advantages over traditional finishes in machining small radii. In addition to the characteristics described above and the effects regarding the addition of pigments and additional substances that absorb energy, preferably additional substances that absorb light and / or radiation and / or heat, mineral fillers or metal particles, the rigidity of the entire finish during processing, in particular for processing in small radii, is still reduced by increased flexibility of the melt layer, and an additional improvement in the ability to deform the tape for the edge when applied and ribbons for the edges on the furniture panel.

The application of edge tapes to the edges of wood-based panels is performed under the influence of pressure and temperature. If the tape for the edge, the melt layer of which was melted by heat, for example by means of a laser, is pressed onto the material, then part of the molten material of the melt layer penetrates into the cavities and pores of the wood-based material; another part extends laterally on the upper and lower edges of the wood-based panel, and another part of the melt layer material remains between the wood-based material and the upper layer of the edge band. After cooling and hardening, the material that passed along the side must be removed by rolling along with the protruding parts of the edge tape. When this material is removed by rolling the edge of the edge band, it is simultaneously or sequentially subjected to subsequent processing to obtain a visually acceptable transition between the surface of the furniture panel and the edge band. This process often causes damage to traditional finishes with a higher modulus of elasticity. This damage can be reduced or prevented using the edge band according to the invention with a reduced modulus of elasticity.

The use of copolymers of polyolefins of the melt layer also increases the impact resistance of the edge band according to the invention. Thus, it is possible when the comparison is performed with traditional edge tapes in order to achieve a sufficient reduction in the number of tears that occur during machining and during use.

In the end, the use of copolymers of polyolefins of the melt layer also reduces the melting point of the melt layer. Firstly, this provides an additional improvement in the rheological properties of the material of the melt layer. Effects and benefits of improved rheological properties of the layer

- 5,032,688 melt have already been described several times above. Secondly, to melt the melt layer, less energy is required with the resulting large energy savings and the associated large cost savings during the application of the edge band according to the invention to the edges of wood-based panels. Alternatively, it is possible to use an increased production rate to bring the edge bands into contact with furniture panels during the production process, with the resulting increase in the productivity of the process for producing furniture panels.

In the melt layer of the edge band according to the invention, for example, homopolypropylenes whose melting point is 163 ° C can be used. The melting point of the used copolymers of polypropylene and polyethylene is, for example, 130 ° C. The melting temperature of the melt layer can preferably be reduced to 160 ° C or lower, preferably 150 ° C or lower, or particularly preferably 140 ° C or lower, by selecting the appropriate ratio of the components of the mixture of homopolypropylene and copolymer of propylene and polyethylene.

Another advantage of the edge band according to the invention is that it provides a substantially better fillet weld when applied to wood substrates. The weakening of edge tapes from the prior art is special in that only a weak adhesive bond is reached in places where the melt layer containing both polar and non-polar particles in the molecule structure coincides with the non-polar upper layer of another edge tape (t i.e. the angle of the furniture component), since the polar and non-polar particles of the tape for the edges, which coincide, are not mutually compatible. This point of weakening in the adhesive bond leads to a reduced resistance to water and water vapor. If an edge tape according to the invention based on polyolefins consisting of only non-polar monomers both in the upper layer and in the lower layer is used, then the indicated incompatibilities are not the result of the coincidence of two edge bands, for example, at the corner of a furniture component.

Moreover, a better tight fit of the surface is achieved by a greater penetration depth of the polymer of the melt layer according to the invention into a wood-based material. In particular, due to this, a better resistance to water and water vapor of the resulting processed material is achieved.

In yet another embodiment, an edge tape is provided comprising a melt layer which consists of at least one free-flowing polyolefin, or whose polymer base consists of a free-flowing polyolefin, and which contains other components, in particular in the form of pigments, fillers and additives. The function of the additional components in the melt layer is, for example, providing the required energy input for melting the melt layer or providing partial or uniform coloring of the melt layer. Other additives, pigments or fillers can serve to improve the resistance of the ribbons for edges to light, in particular UV radiation, or to improve the processing properties of ribbons for edges.

Examples of additives suitable as UV stabilizers are organic UV absorbers, such as benzophenones, benzotriazoles, oxanilides or phenyl triazines, or inorganic UV absorbers, such as titanium dioxide, iron oxide pigments, zinc oxide or HALS (light-stabilized amines based on light stabilizers) for example, 2,2,6,6 tetramethylpiperidine derivatives such as bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate.

Antioxidants serve to prevent oxidative degradation of thermoplastic polymers present in the melt layer. Examples of suitable antioxidants are space-hindered amines (space-hindered amine stabilizers, HAS) from the arylamine group, space-hindered phenol derivatives and phenol and phosphite antioxidants, such as the commercially available products of Irganox, Irgafos, Ethanox, Isonox and others .

For ideal melting of the melt layer, it is possible to use additional substances that absorb energy, preferably additional substances that absorb light and / or radiation and / or heat, such as laser pigments, mineral fillers and metal particles. The advantage of this is that the absorption of energy and, consequently, the melting state of the melt layer can especially coincide with the energy source, for example with the wavelength of the laser radiation.

In yet another embodiment, an edge tape is provided, as in any of the aforementioned embodiments, wherein the liquid coating, which contains additional substances that absorb energy, is thermally and / or chemically dried and, accordingly, crosslinked, applied to the melt layer ribbons for the edge. In this regard, a liquid coating can be applied to the melt layer either on the entire surface, or only on some areas or areas. Thus, it is possible to achieve melting of specific spatially defined regions of the melt layer by using an energy source during processing so that the bond position between the edge band and the furniture panel can likewise be precisely determined.

In order to provide better bonding while increasing the adhesion forces between the edge band and wood-based materials, additives having functional groups or polar

- 6,032,688 groups, for example maleic anhydride or isocyanate-based, can be mixed in a known manner with a melt layer. It is preferable that the additives added to the melt layer to improve bonding while increasing the adhesion forces between the edge band and wood-based materials do not have polar groups.

In a particularly preferred embodiment, the melt layer contains only additional components that do not have the function of improving the bonding between the edge band and the wood panel, i.e. increased adhesion between the edge band and wood-based materials. The composition of the melt layer of the edge band according to the invention based on free flowing polymers actually achieves better adhesion than traditional edge bands on wood-based panels.

The edge band according to the invention may have a single layer structure. In an alternative embodiment, the edge band according to the invention comprises two or more layers. In a preferred embodiment, the edge band according to the invention comprises a top layer along with a melt layer. This top layer may, for example, take the form of a decorative layer. In one particularly preferred embodiment, the top layer comprises a combination of homopolymers or a propylene copolymer. In a particularly preferred embodiment, the invention provides an edge tape comprising a top layer that consists of at least one thermoplastic polyolefin, or whose polymer base consists of at least one thermoplastic polyolefin, and which optionally contains other components, in particular in the form of pigments , fillers and additives.

During the processing of edge tapes on small-radius furniture components, it was found that the high rigidity of thermoplastic finishes tends to be problematic, and especially because the finishes exhibit relatively high recovery forces. Therefore, there is only a limited scope in the prior art to achieve a tight connection between the wood-based panel and the finish. A controlled reduction in the stiffness of the finish during processing is achieved by adding additional substances that absorb energy to the top layer of the edge band, which leads to a certain thermal absorption and, consequently, to an increase in temperature in the thermoplastic material of the top layer. This minor addition of energy-absorbing materials, which can also take the form of a coating, improves the rigidity of the entire finish during processing, in particular processing at small radii, and provides easier deformation of the edgeband.

In a preferred embodiment of the present invention, therefore, for ideal absorption of laser radiation and conversion of laser radiation into heat and, accordingly, absorption of the introduced plasma energy, pigments and additional substances that absorb energy, preferably additional substances that absorb light, were added to the upper layers , and / or radiation, and / or heat, mineral fillers, or metal particles.

It is preferable that the thermoplastic polyolefin of the upper layer is a combination of homopolymers or a copolymer of ethylene, propylene and / or butylene. Most preferred is that the thermoplastic polyolefin is a combination of propylene homopolymers or a copolymer of polypropylene and polyethylene.

Accordingly, the present invention provides an edge tape that takes the form of a multilayer, non-sticky edge tape, and has a melt layer that is extremely free flowing in the molten state, with hardness and melting point that can be comparable to hardness and melting point other layers, so that the entire edge band has a constant hardness and melting point. This layer can be melted by introducing energy through, for example, laser radiation or plasma, and therefore, it is possible to attach the edgeband to furniture panels without additional adhesive. In an embodiment of the invention, the melt layer was colored.

Alternatively, however, the invention also provides an edge tape that takes the form of a multilayer, edge tape without an adhesive, and has a melt layer which in the molten state is extremely free-flowing, with hardness and melting point that can be lower than such other layers . If the hardness of the top layer of this type of tape for the edge is maximized, the result is the benefits associated with the properties of long-term use of the tape for the edge, for example, good scratch resistance. The advantages of a melt layer having a higher elasticity and lower melting point have already been discussed above.

In one embodiment, the edge band consists of colored thermoplastic.

Moreover, it is possible to provide the so-called effects of volumetric patterns in the layers. The effects of volumetric patterns are known as those obtained by coextrusion of the same polymer in a composition with varying staining or by non-uniform distribution of the coloring material. The distribution of the different strip-like stains provides an ideal visual reproduction of the decorative effects of wood.

- 7 032688

In yet another preferred embodiment of the invention, there is provided a double or multilayer edge band made by coextrusion. The coextrusion of the melt layer can be carried out in the process directly with the extrusion of other layers and / or by subsequent coextrusion.

It was revealed that lamination of the melt layer in the two-stage process can also be considered predominant. In the first manufacturing step, the melt layer is extruded in the form of a film. Then this film is laminated on the reverse side of the edge tape. During this lamination, a strong bond between the layers is obtained by exposure to heat and pressure in the grinding stack.

Moreover, the melt layer can be obtained by liquid (subsequent-) coating, which hardens as a result of crosslinking, or drying, or cooling of the pre-molten polymer base. This type of bilayer or multilayer structure has the advantage that the melt layer, the intermediate layers and the upper layer can be composed separately according to their functions. The intermediate layers can act as adhesion promoters between incompatible polymers that cannot be combined by coextrusion (for example, between ABS and PP).

The present invention preferably provides a two-layer edge tape consisting of an upper layer of the aforementioned polymers and a coextruded melt layer based on a free-flowing polymer whose chemical base is the same as defined above.

It is possible to use the same polymer base in the upper layer and in the melt layer. Thus, it is possible to set a high level of uniformity of performance, hardness and softening temperature of the entire edgeband so that it is not possible to visually see any differences in color, gloss and / or structure of the product after machining the edgeband after attaching to the furniture panels.

In yet another preferred embodiment, an edge tape is provided, as in any of the aforementioned embodiments, where a liquid coating is applied to the melt layer of the edge tape and it contains additional substances that absorb energy and is dried by thermal and / or chemical means and , respectively, stitched. In this regard, a liquid coating can be applied to the melt layer either on the entire surface, or only on some areas or areas. Thus, it is possible to achieve melting of specific spatially defined regions of the melt layer by using an energy source during processing so that the bond position between the edge band and the furniture panel can likewise be precisely determined.

In yet another preferred embodiment of the present invention, an edge band is provided, as in any of the above embodiments, wherein the melt layer was coated with an adhesion promoter. The term “adhesion promoter” means a liquid mixture that contains the main components — water and / or organic solvents, binders (eg EVA, PUR, PVC) and mineral fillers (eg silica). Crosslinking agents (e.g., isocyanates) can also be added to increase adhesion values.

In yet another preferred embodiment of the invention, an edge band is provided, as in any of the above embodiments, wherein the melt layer and / or the intermediate layers have / have a foam structure, or the foam structure is obtained by melting or processing the melt layer. The foam structure can be obtained by either physical or chemical foaming of the polymer layer. It was found that the absorption of energy of the melt layer (for example, after laser irradiation) increases. Thus, it is possible for the same quality of adhesive bonding to decrease the power (for example, a laser), and / or increase the production rate of the bonding process, and / or decrease the concentration of energy absorbing additives. All of the above features result in lower costs.

The present invention also provides a furniture panel that is firmly bonded and / or interlocked to one of the edge bands described above. This furniture panel preferably consists of wood, wood-based materials or wood-based materials. Alternatively, this type of furniture panel may also consist of plastic, metal, one or more glasses, stone, ceramics, or a combination thereof.

Moreover, the present invention also provides a method for producing an edge band according to the invention. It is preferable to obtain the tape for the edges according to the invention by extrusion or coextrusion.

In an alternative embodiment, the edge band according to the invention can be made by applying a melt layer according to the invention, i.e. a melt layer consisting of at least one thermoplastic polyolefin onto an existing edge band that does not yet have a melt layer in order to ensure its welding with the furniture panel.

The examples and graphics below provide an additional explanation of the invention.

In FIG. 1 to 3 show an edge band according to the invention, which has been applied to a wood-based panel 3. The tree-based panel 3 is an MDF sheet. Edgeband contains

- 8 032688 top layer 1 and melt layer 2. Groove 4 (0.9 * 2.0 mm) is made in a wood-based panel 3 to determine the penetration depth of the molten melt layer 2 (see Example 6).

Examples 1-5.

Eight colored edge tapes, implemented as double-layer edge tapes, comprise a top layer and a bottom layer.

PP based finish:

upper layer:

PP based homopolymer;

with or without PP-based copolymer (PP / PE);

with or without TPE elastomers;

with fillers (chalk, talc, wollastonite, kaolin) or without them;

with or without pigments;

with or without additives.

Functional layer:

1st example.

50% PP-based homopolymer with MFI 1200;

40% PP-based homopolymer with MFI 100;

10% pigments / additives.

2nd example.

30% PP-based homopolymer with MFI 1200;

60% PP-based homopolymer with MFI 100;

10% pigments / additives.

3rd example.

10% PP-based homopolymer with MFI 1200;

80% PP-based homopolymer with MFI 100;

10% pigments / additives.

4th example.

30% PP-based homopolymer with MFI 1200;

40% PP-based homopolymer with MFI 100;

20% copolymer based on PP / PE;

10% pigments / additives.

5th example.

9% PP-based homopolymer with MFI 1200;

81% PP-based homopolymer with MFI 120;

10% pigments / additives.

6th example.

22.5% PP-based homopolymer with MFI 1200;

67.5% PP-based homopolymer with MFI 120;

10% pigments / additives.

7th example.

45% PP-based homopolymer with MFI 1200;

45% PP-based homopolymer with MFI 120;

10% pigments / additives.

Example 5. The correlation between the MFI of the melt layer and the distance of the flow and adhesion properties.

Plastic finishes 1-3 were made with the definition of the composition of the melt layer in the table. 1. The thickness of the melt layer is approximately 0.2 mm. Along with the listed polymers, the melt layer was painted white and contained an IR absorber as an additive. Finishes were processed in a device for gluing edges using a diode laser assembly with a nominal power of 25 J / cm ² .

- 9 032688

Table 1. The compositions of the layers of the melt

Functional Layer Composition

Composition number PP-based polymer MFI (230 ° C / 2.16 kg) in accordance with ISO 1133 [g / 10 min] of the polymers used Mix ratio 1 A 1200 10 IN 120 90 2 A 1200 25 IN 120 75 3 A 1200 fifty IN 120 fifty

In the table. 2 shows the results of a test for depth of flow of a melt layer and of a peeling test using a drum. The depth of flow was tested by obtaining cross sections as shown in FIG. 1-3, and studying them under a microscope using reflected light with an optical scale.

In FIG. 1 shows a cross section through a tape for an edge whose melt layer 2 was obtained using composition No. 1 (see table).

In FIG. 2 shows a cross section along the tape for the edge, whose melt layer 2 was obtained using composition No. 2 (see table).

In FIG. Figure 3 shows a cross section along the tape for an edge whose melt layer 2 was obtained using composition No. 3 (see table).

The tree panel 3 in FIG. 1-3 is a 19 mm thick MDF sheet. The image in FIG. 1-3 are not to scale.

All tests were performed three times or in each case with three parallel samples. The results set forth in table. 2, in each case represent the average of three trials.

Table 2. Test Results

Depth of flow Drum peeling test (100 mm / min) No. composition Max. Penetration depth (0.9 x 2.0 mm groove in MDF sheet) [mm] Groove fill level [%] The average value of the peeling force for chipboard [N] The average value of the peeling force for the sheet MDF [N] 1 0.82 80 47 46.5 2 0.85 90 56 83.0 3 0.90 100 66 197.5

It is clearly seen that it is possible to influence / control not only the penetration depth, but also the adhesion between the finish and the panel using polymers of different MFI values. With increasing MFI (mixture) increase, and thus, the values of the depth of flow and adhesion are improved.

Improving adhesion is especially apparent when using MDF sheets as a backing material. The advantage of a greater depth of flow is that cracks, which are generally present in practice in the material of the panel surface, are filled more satisfactorily with flowing material based on the functional layer. It is clearly seen that in the case of the tests shown in FIG. 2 and 3, the cavity 5 of the groove 4 is filled more satisfactorily (Fig. 2) or completely (Fig. 3).

The resistance of water and steam coupled at the edges of the panels is therefore increased, and the risk of swelling of wood-based panels is thus reduced. At the same time, in some cases, there is a marked decrease in the residual thickness of the melt layer with increasing MFI

- 10 032688 (mixture) due to the improved flow of the melt layer (see reducing the thickness of the melt layer 2 in FIGS. 2 and 3 in comparison with FIG. 1). In this case, it was found that a large edge of the melt was obtained between the panel and the finish, which, in turn, favorably affects the tight fit of the panel to the finish.

Keywords.

- Upper layer;

- melt layer;

- panel based on wood;

- groove;

- cavity.

Claims (29)

CLAIM 1. Tape for the edges of furniture panels, containing a melt layer, which consists of at least one free-flowing polyolefin, characterized in that at least one free-flowing polyolefin is selected from propylene copolymers; combinations of various homopolypropylenes; combinations of propylene copolymers or combinations of at least one homopolypropylene and at least one propylene copolymer, wherein the free-flowing polyolefin consists of only non-polar monomers and the melt flow index (MFI) of the homopolypropylene is 100 g / 10 min or more, and the melt flow indices of the propylene copolymers are 3 g / 10 min or more (in accordance with ISO 1133, 230 ° C, 2.16 kg). 2. The tape for the edge according to claim 1, characterized in that the free-flowing polyolefin is a copolymer of propylene. 3. The tape for the edge according to claim 1, characterized in that the free-flowing polyolefin is selected from a combination of at least two homopolypropylene, or a combination of at least two copolymers of propylene, or a combination of at least one homopolypropylene and at least one copolymer of propylene, the various homopolypropylene and propylene copolymers present in the combination have different melt flow indices (MFI), and the melt flow indices of homopolypropylene are in the range from 100 g / 10 min to 1500 g / 10 m in, preferably in the range from 100 g / min to 1200 g / 10 min (in accordance with ISO 1133, 230 ° C, 2.16 kg). 4. Edge banding according to any one of claims 1 to 3, characterized in that the melt flow indices of the propylene copolymers are 50 g / 10 min or more (in accordance with ISO 1133, 230 ° C, 2.16 kg). 5. An edge tape according to any one of claims 1 to 3, characterized in that the melt flow index (MFI) of the free-flowing polyolefin is 200 g / 10 min or more, preferably from 400 g / 10 min to 1000 g / 10 min (in according to ISO 1133, 230 ° C, 2.16 kg). 6. Tape for edges according to any one of the preceding paragraphs, characterized in that the propylene copolymers are copolymers of polypropylene and polyethylene. 7. Tape for the edge according to any one of the preceding paragraphs, characterized in that the modulus of elasticity of the melt layer is 1400 MPa or less, preferably 1200 MPa or less. 8. Tape for the edge according to any one of the preceding paragraphs, characterized in that the melting temperature of the melt layer is 160 ° C or lower, preferably 150 ° C or lower. 9. Tape for the edge according to any one of the preceding paragraphs, characterized in that the melt layer contains other components, in particular in the form of pigments, fillers and additives. 10. Tape for the edge according to any one of the preceding paragraphs, characterized in that it has a top layer associated with the melt layer. 11. Tape for the edge according to any one of the preceding paragraphs, characterized in that the main polymer of which the melt layer consists is the same polymer from which other layers of the tape for the edge were made, in particular the upper layer. 12. An edge tape according to any one of the preceding paragraphs, characterized in that the top layer consists of a polyolefin selected from homopolypropylene, or propylene copolymers, or a combination thereof, and optionally other components selected from pigments, fillers and additives. 13. Tape for the edge according to any one of the preceding paragraphs, characterized in that the hardness and melting temperature of the melt layer are comparable to the hardness and melting temperature of other layers of the tape for the edge, and the entire tape for the edge has a constant melting temperature. 14. Tape for the edge according to any one of the preceding paragraphs, characterized in that the thickness of the tape for the edge is preferably in the range of essentially from 0.3 to 4 mm and the visible upper side is laminated with plastic foil or metal foil, and / or stamped , and / or printed and / or coated. - 11 032688 15. Edge tape according to any one of the preceding paragraphs, characterized in that after applying the edge tape to a wood-based panel, in particular a furniture panel, the residual thickness of the melt layer is> 0.02 mm, preferably> 0.05 mm. 16. Tape for the edge according to any one of the preceding paragraphs, characterized in that it has a three-dimensional pattern formed by coextrusion of the same polymer, which is contained in the composition with different colors, or by heterogeneous distribution of the coloring substance. 17. Tape for the edge according to any one of the preceding paragraphs, characterized in that it is made in the form of two or more layers by coextrusion, and the coextrusion of the melt layer can be carried out directly with the extrusion of other layers, and / or by subsequent coextrusion, and / or by lamination melt layer in the form of foil to other layers of tape for the edge. 18. Tape for the edge according to any one of the preceding paragraphs, characterized in that it is made in the form of two or more layers, the melt layer being obtained by applying a liquid coating that hardens by cross-linking, or drying, or cooling the pre-molten polymer base of the melt layer. 19. Tape for the edge according to any one of the preceding paragraphs, characterized in that it is made in the form of a multilayer tape and has at least one intermediate layer, which is an adhesion promoter between incompatible polymers that cannot be combined by coextrusion. 20. Tape for the edge according to any one of the preceding paragraphs, characterized in that it is made in the form of a multilayer tape and has at least one intermediate layer as an adhesion promoter between the melt layer and the upper layers. 21. The tape for the edge according to any one of the preceding paragraphs, characterized in that it has the same polymer base in the upper layer and in the melt layer, while the polymer base ensures uniformity of subsequent operational characteristics, hardness and softening temperature of the entire tape for the edge, and prevents visual differences in color, gloss and / or texture after machine processing of the edge band after attaching to the furniture panel. 22. Tape for the edge according to any one of the preceding paragraphs, characterized in that pigments are added to the melt layer to absorb the introduced plasma energy and additional substances that absorb energy, preferably additional substances that absorb light and / or radiation and / or heat , mineral fillers or metal particles. 23. Tape for the edge according to any one of the preceding paragraphs, characterized in that the pigments and additional substances that absorb energy are added to the upper layers of the tape to absorb laser radiation and convert laser radiation into heat and, accordingly, absorb the introduced plasma energy, preferably additional substances that absorb light and / or radiation and / or heat, mineral fillers or metal particles. 24. Edge tape according to any one of the preceding paragraphs, characterized in that the liquid coating is applied to the melt layer of the tape and contains pigments and additional substances that absorb energy, preferably additional substances that absorb light and / or radiation and / or heat mineral fillers or metal particles, and dried by thermal and / or chemical means and, accordingly, crosslinked. 25. Tape for edges according to any one of the preceding paragraphs, characterized in that the adhesion promoter is applied to the melt layer and consists of a liquid mixture containing the main components, water and / or organic solvents, binders and mineral fillers. 26. Tape for the edge according to any one of the preceding paragraphs, characterized in that the melt layer and / or the intermediate layers has / have a foamed structure or a foamed structure obtained by melting or during processing of the melt layer. 27. Furniture panel with a tape for an edge according to any one of the preceding paragraphs, characterized in that in separate sections or over the entire surface there is a strong connection between the melt layer and the edge of the furniture panel. 28. The furniture panel according to item 27, wherein the materials of the furniture panel consist of wood, materials based on wood, materials based on substitutes for wood, plastic, metal, glass, stone, ceramics, or a combination thereof. 29. A method for producing an edge tape according to any one of claims 1 to 26, characterized in that the melt layer defined in any one of claims 1 to 9 is applied to the top layer of the edge tape.